Syria's president said his government will make every effort to ensure the success of U.N. envoy Kofi Annan's peace mission, but the plan will work only if it vanquishes support for terrorism.

Bashar al-Assad gave the conditional assurance in a letter to representatives of the world's top emerging economies who were meeting in New Delhi, the state-run Syrian Arab News Agency said.

Earlier this week, the Syrian regime accepted Annan's six-point initiative, but activists and diplomats said violence continued across the nation two days later. Security forces shelled and stormed various cities, leaving at least 60 people dead Thursday, including six children, four women and six people who were killed while being tortured, activists and the opposition Local Coordination Committees of Syria said.

In his letter, al-Assad expressed hope that Annan will deal comprehensively with the crisis, "in particular the international and regional ones," the news outlet said. He said Syria is also willing to conduct a national dialogue with the participation of groups seeking "security and stability."

He also said that, for Annan's mission to succeed, he should focus on drying up sources supporting terrorism against Syria, especially by countries that have said they are financing and arming Syrian "terrorist groups."

"In return for a formal commitment by Syria for the success of Annan's mission, it is necessary for him to obtain commitments from other parties to stop all terrorist acts, disarm gunmen and to end their terrorist acts, kidnapping, killing innocents and sabotaging infrastructure of both public and private sectors," SANA reported, quoting al-Assad. He wrote the letter to the BRICS summit, whose acronym stands for Brazil, Russia, India, China and South Africa.

Syria routinely blames armed terrorist groups for violence in the country, while most reports from inside the nation suggest the government is slaughtering civilians in an attempt to wipe out dissidents.

The opposition Syrian National Council and the Free Syrian Army fighters have leadership in neighboring Turkey. Arms are reportedly smuggled to fighters to Syria from neighboring countries, and Arab officials have supported arming the rebels.

Annan, a former U.N. secretary-general, is the joint special envoy for the Arab League and the United Nations. His plan calls for an end to the violence by the government and opposition, timely humanitarian aid, speeding the release of "arbitrarily detained" people, ensuring freedom of movement for journalists and respecting peaceful demonstrations and freedom of association.

Leaders at the Arab League summit, which opened Thursday in Baghdad, urged al-Assad to carry out the plan.

Arab League Secretary-General Nabil Elaraby said dealing with the Syrian crisis is the U.N. Security Council's responsibility.

The Syrian people have the right to determine their own future, the Arab League said. It stressed a peaceful transfer of power, the condemnation of violence and killing, an end to the bloodshed, a political solution, national dialogue and rejection of foreign interference in the Syrian crisis.

U.N. Secretary-General Ban Ki-moon said there is no time to waste.

"The conflict in Syria is on a dangerous trajectory with potential ramifications for the entire region," Ban told the Arab League. "It is essential that President Assad put those commitments into immediate effect. The world is waiting for commitments to be translated into action. The key here is implementation."

While Ban said the Syrian regime has subjected its citizens to military assault and a disproportionate use of force, he also called on the opposition to cooperate with Annan's proposal.

Annan intends to join the U.N. Security Council in a private meeting Monday in which he will brief members on his plan.

Meanwhile, Britain gave Syria's political opposition a boost Thursday with nearly $800,000 for "nonlethal" support. The nation has made other donations to Syrian opposition entities over the past eight months.

UK Foreign Secretary William Hague said the money will help opposition and civil organizations both inside and outside Syria to document the regime's violations and start building their skills and resources for a "democratic future for Syria."

Hague said he would send a "clear warning" to al-Assad and his allies in Istanbul on Sunday at a meeting of Friends of Syria, a coalition of nations seeking tough action against his regime.

"They must be left in no doubt that if there is not a political transition that reflects the will of the Syrian people, then they will be shunned by the international community and we will close every door to them," Hague said.

U.S. Secretary of State Hillary Clinton plans to meet Friday and Saturday with Gulf officials in Saudi Arabia to discuss Syria.

The United Nations estimates that the Syrian conflict has killed more than 9,000 people since a government crackdown on protesters began last March. Opposition activists put the toll at more than 10,000.

At least 1 million Syrians are in need of humanitarian assistance, U.N. deputy spokesman Eduardo del Buey said Thursday.

CNN cannot independently confirm reports from inside Syria because the government severely restricts access by international journalists.